Process of bating hides and skins.



. remainder of the epidermis, the dissolved OTTO noun, or srurroanr, GERMANY.

PRGSEEIS OFZQBATIN'G HIDES AND SKINS.

Specification of Letters Patent.

Patented Zinc. 31, 196?.

Application filed August-.18. 1906. Serial No. $31.21!):

To all whom it may concern:

Be it known that I, OTTO Bonn, Ph. 1)., a citizen of the Empire of Germany, residing in Stuttgart, in the Kingdom of Wiirtemberg, in said Empire, have invented certain new and useful improvements in Process of Bating Hides and Skins, of which the following is a specification.

This invention relates to an improved process of hating hides and skins.

The well known liming processes to which the hides and skins were heretofore subjected for loosening the hair and the epidermis, leave in the hides and skins an undesirable proportion of. lime so that they assume a swelled, plumped condition.

' It is the object of my improved hating process to remove these undesirable properties and to facilitate the removal of the ground-hair and the so-oalled dirt, viz., the

hair-bulbs, the fatty matters which had been saponified by the lime, and the coriin, the liquid part of the hide substance which, dur: ing the liming process, has combined with the lime.

By my resent invention the eflect, heretofore obtained by the animal dung bate, is obtained in a very effective manner by chemical means in the following manner: After the well known unhairing or depilation process, the hides and skins are subjected to the action of an aqueous bath at about 85 F., containing suifureted hydrogen, carbonic acid and ammonia in the following proportions: To 100 arts or weigh units of water 'are adder 1/10 part of sulfureted hydrogen. (flfi), one part of carbonic acid (H COQ) and 7/10 parts of ammonia (N11,). The volume of the solution. is approximately in the proportion of 30 gallons of the solution to 100 lbs. of moist hides or skins. These proportions and the temperature may, however, be varied somewhat according to the season, the condition of the water and according to the s ecial requirements of the various kinds of hides and skins.

A simple way of preparing the solution is the following: According to the above given proportions, 100 gallons of water require 13.35 oz. of sulfureted hydrogen, 133 1/2 oz. of carbonic a d, and 93 1/2 oz. of ammonia, which are obtained by adding to-the water 133% oz. of asolutiori of ammonium sulfid containing 10% H 8 and 10% NB yielding 13.35 oz. H 3 and 13.35 oz. EH 203 1/2 oz. of ammonium carbonate of commerce, con: taining 46.6% OO,=-65.6% Pl GO and 26% NH yielding 133 1/2 oz. H CQ, and 52.9

oz. NH and 136 1/4 oz. of aqua ammonia of 20% strength. The quantity of NH, needed is 93 1/2 on? The solution of ammonium sulwhich leaves to be added 27 1/4 oz. NH 136 1/4 oz.of 20% hill The aqueous solution thus prepared com tains ammonium sulfid= (NHQ S, ammoni um carbonate= (NHQZCO and a smafl percentage of ammonia=NH according to the above given figures. The hides and skins transferred into this liquor are stirred for about 20 to 30 minutes and are then to remain therein for about 4 to 8 hours under occasional stirring, after which they are ready for further treatment.

By subjecting the hides and skins to this solution, the lime 1S transformed into insoluble calcium carbonate which is indicated, shortly after the reaction,

by the milky turbidityof the hating liquor, and the hides and skins are caused to fali from their swelled, plumped condition. The pores are gradually opened so that the dirt and the ground-hair can be readily removed in the usual manner; The hides and skins become soft and pliable and show a low, smooth and brilliant grain. The final leather roduced shows, when dyed, a uniform and rilliant color.

To the water into which the hides and skins are to be transferred after the hating, are added'ab0ut 3% of the used batin liquor in order to precipitate the lime or 'narily contained in the water, as otherwise the ammonia and ammonium carbonate still contained in the hides'and skins would cause the formation of insoluble calcium carbonate which in statu nascendi would settle on claim as new and desire to secure by Letters Patent: The process herein described of hating presence of two subscribing witnesses.

hides and skins WhiCh consists in subjecting OTTO RQHM. -5, the same to the action of an aqueous solution of sulfureted hydrogen, carbonic acid and ammonia.

Witnesses 1 EMIL SEIPPEL, ALFRED LQROHER.

In testin ony that I claim ti'1eforogsing as my mventlon, I have slgned my nmne in 

